Cracks in the finished paint on sealed structural joints associated with aerospace components (e.g., joints between adjacent panels associated with a fuselage, engine nacelles, wing skin panels, empennage panels, fairings and the like) has been an issue in the industry which adversely impacts the visual aspects of the finished paint scheme. The issue is particularly acute for the fuselage paint on executive jets where a high quality and visually pleasing paint finish is an important customer requirement. However, cracks in the finished paint along structural joints of the fuselage associated with commercial aviation aircraft is also a very common problem.
Cracks in the finished fuselage paint occur due to the difference of mechanical properties of the materials used at the structural joints (e.g., differences in mechanical properties of the sealant, the metal panel (typically aluminum), and finish paint). These mechanical property differences in turn create localized strain on the finished paint layer when the structure experiences a load, e.g., due to forces caused by internal fuselage pressurization forces and external aerodynamic forces. The consequence of such forces is that the paint visibly cracks along the lengthwise extent of the joint.
It has previously been proposed in this art to create a gap in the sealant between the structural panels before applying the final paint coating. However, this proposed solution has limitations due to the visual aspect of the gap and lack of aerodynamic smoothness. As such, this prior proposal has essentially been limited for use mainly on fairings joining the wings to the fuselage and maintenance access doors.
What has been needed in the art, therefore is a system by which the finished paint covering structural joints of an aerospace component (e.g., an aircraft fuselage) could be protected against cracking. It is towards fulfilling such a need that the embodiments disclosed herein are directed.